From e5d219949eb2255137fd012274ff0d20a6f002c6 Mon Sep 17 00:00:00 2001
From: Madhura Ingole <121611425+madhura-ingole@users.noreply.github.com>
Date: Sun, 4 Aug 2024 01:02:18 +0530
Subject: [PATCH] Create minStack.cpp

Program to retrive minimum element in constant time.
---
 C++/minStack.cpp | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 C++/minStack.cpp

diff --git a/C++/minStack.cpp b/C++/minStack.cpp
new file mode 100644
index 0000000..99bc3ae
--- /dev/null
+++ b/C++/minStack.cpp
@@ -0,0 +1,37 @@
+class MinStack {
+public:
+    stack<long> st;
+    long long min=INT_MAX;
+public:
+    MinStack() { 
+    }
+    
+    void push(int val) {
+        long long value = (long)val;
+        if(st.empty()){
+            min=value;
+            st.push(value);
+        }
+        else if(val<min){
+            st.push(2*value-min);
+            min=value;
+        }
+        else st.push(value);
+    }
+    
+    void pop() {
+        if(st.empty()) return;
+        if(st.top()<min) min=(2*min - st.top());
+        st.pop();
+    }
+    
+    int top() {
+        if(st.empty()) return -1;
+        if(st.top()<min) return min;
+        return st.top();
+    }
+    
+    int getMin() {
+        return min;
+    }
+};